The present disclosure relates to a method of controlling and/or regulating a centrifuge for the centrifugal production of a milk product. It also relates to a system for implementing the method.
It is known to, for example, separate milk into skimmed milk and cream by centrifuges. Disk separators are generally used for this purpose.
During the separation into skimmed milk and cream, it is a goal of the centrifugal separation to minimize the fat content in the skimmed milk as much as possible in order to design the economical yield of the method to be as optimal as possible.
Unfortunately, the determination of the fat content of cream or skimmed milk is relatively problematic since the skimmed milk or the cream have a white coloring, so that methods for determining the light transmittance of the skimmed milk are high-expenditure (laboratory) processes, such as the process by Röse-Gottlieb and the process by Mojonier with precisions or a reproducibility of 0.03% and 0.015%.
The present disclosure provides for a method of controlling and/or regulating a centrifuge for the centrifugal production of a milk product as well as a system for implementing the method. The controlling and/or regulating of the centrifuge is simplified and a determination of the fat content becomes possible which is as precise as possible, and is simpler in comparison to the known laboratory processes and is independent of the latter.
Thus, the present disclosure relates to a method of controlling a centrifuge for the centrifugal production of a milk product. The method steps comprise: taking a milk sample at an outlet of the centrifuge from a liquid phase; adding a substance to the milk sample that increases light transmittance of the milk sample; determining the light transmittance of the milk sample by transilluminating the milk sample using a light source and measuring light intensity via a photo cell; determining fat content of the milk sample from a measurement of the light transmittance; and controlling the centrifuge as a function of the determination of the fat content.
The liquid phase from which the mild sample is taken may be skimmed milk. Furthermore, it should be noted that, by adding the substance, such as a suitable alkaline solution, to the milk sample, the pH-value is increased. It then becomes possible in a simple manner to increase the light transmittance of the white milk sample to such an extent that surprisingly it is possible to use an optical method for determining the fat content. The determination of the fat content can be carried out in intervals by a computer in an automated manner. If the computer, in turn, is connected with the control inputs of the actual centrifuge control, or the computer is even used for controlling the centrifuge, it becomes possible to utilize the information not only for monitoring the setting of the centrifuge but also for its controlling and/or also for the regulating as a function of the determination of the fat content. However, a manual monitoring by a person reading a display unit can also be implemented.
The light transmittance of the liquid phase, particularly of the skimmed milk, is increased in that the substance increasing the pH-value is proportioned and added such that the pH-value of the milk sample is increased to 11–14, preferably 12–13, and particularly to 13.
The present disclosure also relates to a system for controlling a centrifuge for the centrifugal production of a milk product. The system includes a device that takes a milk sample from a liquid phase at an outlet of the centrifuge. Also included is a device that adds a substance to the milk sample that increases light transmittance of the milk sample. Further included is a device that determines the light transmittance of the milk sample and from which a fat content of the milk sample is determinable. With regard to the system, it can be constructed, for example, as a separate unit and assigned to or connected with the centrifuge. Further, a device for controlling and/or regulating the setting of the centrifuge as a function of the determined fat content may be preferably assigned to or connected with the device for determining the light transmittance.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.